On 03/11/12 03:03, Jesus Garcia wrote: > Sorry for post something posted in firebird support, but i have not had any > response and may be developers can do. > > I'm trying to understand the memory usage with classic server 2.5.2 32/64 > bits with cache pages set to 75/300. > > Our production database, once one form is opened, uses around 120000 Kb > memory in Fb 2.5 64 with 300 Cache pages.The memory is allocated the first > time a form that open a set of tables that is related with many other > tables in the database with the table's triggers. I think the memory > allocation is for metadata, because just preparing the querys, the memory > consumption increases. If i comment one trigger the memory decreases to the > half, but the triggers are needed. > > Once that table is opened, the memory usage ( Working Set ) for > fb_inet_server is between 120000 Kb and 130000 Kb. That makes the memory > consumption for 150 users around 20-24 Gb. I'm trying to understand haw can > I avoid using so much RAM, if i can. > After I close the form, the transaction and the tables, the memory > consumption is the same, but after some minutes i see that the memory > consumption (Working Set) decreases and uses between 8 and 15 Mb. After > that if i reopen again the form that opens the tables that makes > fb_inet_server uses a lot of memory, then the memory consumption in > fb_inet_server is between 20 Mb and 30 Mb, what i see normal. Working after > that with the app, never uses more than 50 MB, but never less than 25 MB > > After that i have created a test program that opens a connection to the > database, opens tha datasets that forces the memory consumption, closes > them and wait with the connection opened. I have downloaded the last builds > of fb 2.5 for 32 and 64 bits and have runned the test over firebird 32 and > 64 bits in a Windows 7 64 bits workstation. > > I have created 10 connections to both servers with the default > configuration in firebird.conf (75 cache pages). > > 64 bits. Each connection uses 112000 Kb Working Set, while 106364 Private > Bytes > 32 bits. Ecah connection uses 85000 Kb Working Set, while around 80000 > Private bytes > > Waiting some minutes, i see that the working set decreases, process by > process to less than 1 MB. >
That's sooner of a kind of OS-specific effect. Such small working set as 1Mb is too small for firebird. > What is the real RAM needed for each connection? That depends first of all upon the metadata, needed at he given moment of time. > Is there any option to force firebird to free memory used for loading > metadata? Right now not. May be it's possible to have one, but that's not trivial change. > Is there any option for not use so much RAM? Use superserver. > Why 64 bits version uses 27000 Kb than 32 bits more for each connection? Because metadata cache contains a lot of pointers. They are twice bigger in 64 bits case. ------------------------------------------------------------------------------ Virtualization & Cloud Management Using Capacity Planning Cloud computing makes use of virtualization - but cloud computing also focuses on allowing computing to be delivered as a service. http://www.accelacomm.com/jaw/sfnl/114/51521223/ Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
